Enamel composition.



UNITED STATES PATENT OFFICE.

PHILIPP EYER, QF FBANKFORT-ON-THE-MAIN, GIdRIlIANY.

ENAMEL COMPQSITION.

v oDrawing.

TO (lll diom it may concern:

Be it known-that I, PHILH'I. Evian, a subf ject of the German Enq'ieror. residing at Fran'lcfort-oirthe-Main. in the Gern'ian Empire, have invented rcrtainnew and useful lnipr vemrnts.-in Enamel Compositions. of

l under the collective name of borax limev or borate of lune. suchas bororalrite, horarite,

colemanite audthc like, which are employed as raw materials for the mainifacture of' pure borax L p to the present, however,-

borate of lime has not found its way .into

the enamel indu'stq as a substitute "for borax; Thiscircumstance is no doubt due to the faet lhat up to very rerently the opinion was held thatit was necessary to use the purest possible horax for the manufacture of good enamel glazes ll'uweifore theim'pu'rities. particularly the rh'lorids'aml sulfates. contained in the horato of lime nee-.

essaril gave rise to appreheiisimi on that score. The greatest obstacle. tothe use of (rude boax or lmrato ot-lime was however the la rge pcrcrntageot lime. because experience has slurvu that enamel glaze becomes useless if the wreenta ge of lime excecda certain amount. Areording to the present invention. however. natural produetsrcmraining-or yieldingdiorie arid or horax such as are used as the raw materials for the manufacture of borax. for instance horocal-' cite, colemanite. bum-sodium calcite, l'mrarite and the like, are used in the place 'of pure. borax afterthe injurious earthy alkali contained in the borate of lime has been counteracted by adding other ingredients contain ing lime in a proportion reduced according to the excess of lime in the borate oflime, or.

Specification of Letters Patent.

lied.

Patented Nov 24, 1914.

Application filed August 25. 1914. Serial No. 858,512. 7

after the effects of an excessive contentof lime have been counteracted by adding suitable auxiliary substanres.

llithertofor instance for almost all enamel recipes tlnor-sp.-:r has been added as the flux.

' 'ow in arrordanre with the presentinvention in using borate of lime. the addition of fluorspar. for instant-e. will be so regulated that the latter is wholly or in part replaced by sodium fluorld. awarding to the amount of lime contained in the borate of lime. By

this simple means the injurious Content of lime in iluboa-ate of lime can be roun'tor: balanced.

Tho. use 01" lluorids a. a fluxand clouding agent is gear-rally known in the enamelindust ry'. The present invention. lnnvcver, couromponndacontaining lune. by lime free fluorid rompounds in a definite proportion for the I'HHPUSQ. of arhiering a new object,

namely the use of. borate of lime instead of pure b rax. Yin-ample for a. 3.4.3.; siliro-lluorid of sodium S.S. qnartz 10, feldspar 33. soda saltpeter 7.5, Cobalt oxid 0.3.- I

A surprisin; fact in this ronnertion is the rhlorids and sulfates present in small quauhorate of linu: containing only low perrentages of (hlorid and sulfate.

The priming glazes produred by. the aid of borateof lime adhere very firmly t the sists in lt'pltll'lllg the hitl'urto used fluorid.

discovery that theimpuritibs. and even-tho.

v s titles in horate of lune have no in uriousj it is. however. prrferable to use a'rtirle enameled. The rause of this is 'probahly dueto the fact that the salts Contained in the borate of lime have a corrosive efiect on the. surface to be. enameled.

in some raises impurities in the borate of limemay he (ountQrbalahCed similarly to the superfluous lime rontaine'd by adding suit able substances or by suitably selecting the known ingredients to be added to theenamel. in crude. borax materials containing magnesia, the magnesia must. be accounted equal to lime.

W hat is claimed is 1. An enamel composition comprising a natural alkali -ea'rth borato, sili cor fiuorid of sodium; quartz, feldspar, soda,'and salt. In testimony whereof i m; a signed mypeter. name to this specification in the presumzv. 2. An enamel composition comprising the two subscribing witnesses. fnliawing ingredients in substantially the PHILIP? HY 'follmving proportions,boraci'te silicar .Vitnesses:

fiuprid of sodimn 8.8, quartz 10, feldspar 33, JEAN GRUND, soda .12, saltpeter 7.5, cobglt axld 0:3. CARL GRUND. 

